by Dann Stupp, USA TODAY Sports

by Dann Stupp, USA TODAY Sports

Although he was billed as a "Korean Zombie" who could withstand an inordinate amount of damage, even Chan Sung Jung couldn't fight through an injured shoulder.

Jung (13-4 MMA, 3-1 UFC), a title challenger well known for his past durability, became easy prey for UFC featherweight champion Jose Aldo (23-1 MMA, 5-0 UFC) once the injury occurred in the fourth round.

Jung, an injury replacement for Anthony Pettis, entered the five-round fight as a significant underdog and following a 15-month layoff because of injuries. Aldo clearly was getting the better of the challenger early in the fight, but it took a painful injury for Jung to finally succumb to the champ.

After a feeling-out process in the first round, where Jung traded low kicks and quickly scrambled to avoid extended firefights, Aldo closed out the round with a spinning wheel kick and continued the assault in the second round. His combinations got through Jung's defense, and a few well-timed jabs buckled the challenger's legs. A late takedown and guard pass allowed the champ to deliver some elbows, but a crafty Jung avoid any serious damage while on his back.

With timid attacks doing no good, Jung finally took some risks in the third round. However, Aldo quickly snuffed out an early flying knee attempt, and he avoided a second one later in the round. Jung's efforts did little to score points with the judges, but it forced Aldo into a defensive stance.

Aldo's uncharacteristic timidity initially continued into the championship fourth round, but after Jung clearly separated his shoulder while throwing a looping right hand, the champ pounced. Jung attempted to pop his arm back into its joint, but Aldo swarmed an unloaded a barrage of fight-ending punches to force the referee's intervention at the 2:00 mark of the round.

Jung immediately sprung to his feet, but he then grasped his arm and grunted in clear pain. As the injured challenger was helped out of the cage, a triumphant Brazilian champ celebrated his latest title defense with his countrymen.

Aldo, though, knew his opponent gave him an assist.

"I did see that he separated his shoulder, so I kicked him and tried to put him down on the ground to give him some ground and pound," Aldo said.

Even if the injury hadn't occurred, Aldo was winning the rounds and surely would have taken the decision on the judges' scorecards if the fight went the distance. He said his game plan was geared around that.

"I thought if I could take him down and put his back on the floor, I would win the rounds," he said.

Aldo, who was the WEC's final featherweight champion before the organization was folded into the UFC, now has posted seven consecutive title defenses with the two promotions. He's also notched 16 consecutive victories overall.

In the event's co-headliner, light heavyweight Phil Davis (12-1, 8-1) scored a controversial unanimous decision victory over Brazilian karate specialist Lyoto Machida. Machida (19-4, 11-4) appeared to have the edge with the standup, and NCAA Division I national wrestling champion Davis was limited to just a few takedowns. But the judges ultimately favored the American and awarded Davis the victory via 29-28 scores.